In the production of dental restorations such as inlays, crowns, bridges and the like, there have been a number of devices and procedures either developed or proposed for eliminating the use of individual tapered dowel pins for locating the removable dies which are formed by cutting a dental model into sections. Such individual dowel pins are small and difficult to handle, and some form of apparatus, for example, as disclosed in U.S. Pat. No. 4,017,972, is required for positioning the pins within a dental model. Examples of such proposed devices and procedures are disclosed in U.S. Pat. Nos. 3,436,827 and 3,702,027. In these devices, a positive dental model is formed in a conventional manner and then the model or a section of the model is shaped and connected to a moldable base material which is received within a locating tray. When the base material hardens to form a base for the model, the combined model and base are removed from the tray so that the model and base may be cut into sections or separate dies which are placed back into the tray in their original orientation.
Another form of device developed for eliminating the need for individual tapered dowel pins is disclosed in U.S. Pat. No. 3,478,428. In this patent, a plurality of tapered pins are molded of a plastics material and are integrally connected by a base portion which is embedded in and positively connected to the dental model. The base portion is cut into sections when the model is cut into dies so that each die is provided with one or more tapered locating pins which seat within corresponding tapered sockets or holes formed within the molded support base for the model. U.S. Pat. No. 3,581,398 discloses another form of die locator wherein a U-shaped keying device is embedded within the dental model and has a projecting serrated rib portion which is received within a mating recess formed within the support base for the model. This keying device is also cut into sections when the model is cut into dies so that each die is provided with a section of the keying device for locating the die.